The aim of this study is to investigate the role of gluconeogenesis (GNG) in human pregnancy and its implications on fetal growth. It is hypothesized that as gestation advances, the increased fetal and maternal demands for carbohydrate energy are met by increased contribution of hepatic gluconeogenesis. It is further hypothesized that GNG will be further increased in women with gestational diabetes, and that the major mechanism of regulating maternal glucose metabolism by insulin therapy in insulin dependent diabetes mellitus involves suppression of GNG. The biological samples obtained are being analyzed. The data thus far suggest that gluconeogenesis is increased in early gestation and then attenuated later in pregnancy.